298 ON SENSATION AND THE UNITY OF 



knee, says of smell: "It appears to be a simple 

 and original affection or feeling of the mind, 

 altogether inexplicable and unaccountable. It is 

 indeed impossible that it can be in any body: it 

 is a sensation, and a sensation can only be in a 

 sentient thing." * 



That which is true of muskiness is true of 

 every other odour. Lavender-smell, clove-smell, 

 garlic-smell, are, like " muskiness," names of 

 states of consciousness, and have no existence 

 except as such. But, in ordinary language, we 

 speak of all these odours as if they were independ- 

 ent entities residing in lavender, cloves, and gar- 

 lic; and it is not without a certain struggle that 

 the false metaphysic of so-called common sense, 

 thus ingrained in us, is expelled. 



For the present purpose, it is unnecessary to 

 inquire into the origin of our belief in external 

 bodies, or into that of the notion of causation. 

 Assuming the existence of an external world, 

 there is no difficulty in obtaining experimental 

 proof that, as a general rule, olfactory sensations, 



* An Inquiry into the Human Mind on the Principles of 

 Common Sense, chap. ii. 2. Reid affirms that " it is genius, 

 and not the want of it. that adulterates philosophy, and fills 

 it with error and false theory ; " and no douht his own lucubra- 

 tions are free from the smallest taint of the impurity to which 

 he objects. But. for want of something more than that sort 

 of " common sense," which is very common and a little dull, 

 the contemner of genius did not notice that the admission 

 here made knocks so big a hole in the bottom of " common 

 sense philosophy," that nothing can save it from foundering 

 in the dreaded abyss of Idealism. 



